项目作者: S-shangli

项目描述 :
Shellscript for the AQM0802 charactor LCD on RaspberryPi.
高级语言: Shell
项目地址: git://github.com/S-shangli/raspberrypi_aqm0802_print.git
创建时间: 2017-03-10T13:12:29Z
项目社区:https://github.com/S-shangli/raspberrypi_aqm0802_print

开源协议:

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raspberrypi_aqm0802_print

Shellscript for the AQM0802 charactor LCD on RaspberryPi.

settings

item descriptions
I2C_BUS=1 I2C bus No.
LCD_ADDR=”0x3e” LCD I2C slave address

usage

execute with one arg that is strings.

  1. [pi@raspberrypi]% ./print_aqm0802.sh "hello world"

you can see “hello world” in the LCD.

software requirements

  • bash
  • od
  • head
  • sed
  • cut
  • i2cset , i2cget

hardware list

  • RaspberryPi, OrangePi C.H.I.P. and i2cget/i2cset working environment.
  • AQM0802 , AQM1602
  • 2SA1015 (or other PNP tr)

hardware connection

  1. AQM0802 RaspberryPi
  2. +--------+ +-------+
  3. | | | |
  4. | VDD---*----------------------------3.3V |
  5. | | | | |
  6. | RESET---+ | |
  7. | | | |
  8. | SCL--------------------------------SCL |
  9. | | | |
  10. | SDA--------* +-----SDA |
  11. | | | | | |
  12. | GND---*----+-----------------+-----GND |
  13. | | | | | | |
  14. +--------+ | | | +-------+
  15. | | |
  16. 2SA1015 | | |
  17. +------+ | *--[R 100k Ohm]---*
  18. | C-----+ | |
  19. | B----------+ |
  20. | E----------------------------+
  21. +------+
  22. (PNP Tr)
  23. + corner/cross-over
  24. * connect

PNP Tr wrokings

AQM0802, AQM1602 is lower sink power at SDA. they can’t drive-L at I2C bus (SDA).
Therefore I2C communication will fail.
PNP tr is help this problem.